PharmOneHealth - Project N° ANSES-22-EST-066

In line with the ‘One Health’ concept, the combined occurrence of pharmaceuticals (chemical contaminants) and microbiological contaminants (antibiotic resistance genes - ARGs, antibiotic resistant bacteria - ARBs, and pathogenic microorganisms) in aquatic environments poses risks for the ecological quality of these ecosystems as well as for human and animal health. Although this type of co-occurrence is frequently reported in aquatic ecosystems, the interactions between these chemical and microbiological contaminants remain understudied. The PharmOneHealth project aims to contribute to filling this gap by mobilizing scientists and research teams recognized for their complementary skills in the fields of environmental chemistry, microbial ecology and ecotoxicology, as well as environmental and clinical bacteriology.

A project coordinated by Stéphane PESCE, RiverLy - INRAE

The main objective of PharmOneHealth is to assess, in a context of microbiological contamination, the influence of exposure to pharmaceuticals on the implantation and development of pathogenic microorganisms and antibiotic resistant bacterial forms in natural microbial biofilms (communities from periphyton and sediment). Our hypothesis is that the co-occurrence of pharmaceuticals and microbiological contaminations would induce marked shifts in aquatic biofilm structure and diversity including the replacement (species sorting) of some native species by opportunistic forms including pathogens such as those of the ESKAPE group or Achromobacter xylosoxidans.

To test this hypothesis, we will combine experimental studies in laboratory channels with in situ surveys carried out in two rivers, respectively located in rural and urban areas, in order to:

1. characterize (experimentally and in situ) the bioaccumulation kinetics of pharmaceuticals in periphyton and the concentrations in surface sediments and waters in order to better characterize the contamination of the environments and define the exposure levels of the periphytic and sediment microbial communities;
2. determine (in situ) the co-occurrence of pharmaceuticals, pathogenic microorganisms and the abundance and expression of ARGs and virulence genes;
3. determine (experimentally) the influence of exposure levels (concentration and duration) to model pharmaceuticals (the sulfonamide antibiotic sulfamethoxazole, the fluoroquinolone antibiotic ofloxacin and the non-steroidal anti-inflammatory drug, diclofenac), alone or in mixtures, on i) the kinetics of microbial community shifts and tolerance increase (pollution induced community tolerance – PICT), ii) changes in the abundance and expression of ARGs and virulence genes and iii) the evolution of the resistance phenotype of some pathogenic bacteria;
4. evaluate (in situ) the relevance of the methods used and developed in the project (to monitor the chemical and microbiological quality of rivers (including bioaccumulation measurement, PICT approaches, electrochemical measurement of enzymatic activities, and DNA arrays and metatranscriptomics approaches.

As a whole, PharmOneHealth will address several issues : i) the characterization of exposure levels to chemical and microbiological contaminants in aquatic ecosystems for environmental biomonitoring, through the application of complementary tools based on chemical, molecular and functional analyses; ii) the behavior and fate of pathogens in aquatic environments and their potential risks on human health and; iii) the impacts of co-exposure to chemical and microbiological agents on ecosystems and human health.